MEMS refer to a technology field fabrication a sensor, a micro actuator or a gyroscope by using a semiconductor fabrication technology. Accordingly, precision processing, uniformity of products, and high productivity of the semiconductor technology are applied to the MEMS, and performance thereof is enhanced and cost is reduced.
MEMS devices, for example, an acceleration sensor, a gyro sensor, and a resonant gyroscope are packaged for protection or sensitivity increase. As the rapid development of the MEMS device manufacturing technology, high density and miniaturization of the MEMS device are realized and accordingly, miniaturization of a package thereof is necessary.
Accordingly, a wafer level packaging is frequently attempted which performs packaging in a wafer state having a device formed thereon.
A MEMS device package by typical wafer level packaging has a structure in which a substrate for a glass-based cover and a substrate for a silicon-based device are joined by anodic-bonding. However, due to the thickness of the glass substrate for the cover, the thickness of the package becomes greater and, due to large via holes formed in the glass substrate, there is limitation in reducing the size of the package. Using such a large size MEMS device package results in disturbing minimization of the device.
In addition, since a method of arraying each device on a plane in a unit device state and using a wire bonding process maintains air-tightness by using a cap on the device in the case where hermetic characteristics of the MEMS device is required, the package dimension of the entire package is large and a process thereof is complex.
An aspect of the present disclosure provides a MEMS sensor packaging and a method thereof capable of reducing a size of a package and stably providing an electric signal by forming internally pad solders for electrically connecting a readout integrated circuit (ROIC) and a MEMS sensor in joining and packaging a wafer having the ROIC circuit formed thereon and a wafer having the MEMS sensor formed thereon.
Technical issues of the present invention are not limited to those described above and other technical issues will be clearly understood by those skilled in the art from the following description.